JP2012023979A - Raceway-pond type culture tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a raceway-pond type culture tank capable of controlling the culture cost and permitting dissolution of a sufficient amount of carbon dioxide in a culture solution even in a shallow depth of water.SOLUTION: The raceway-pond type culture tank includes: a stirring means in a culture channel 8 through which the culture solution M flows, with the stirring means stirring the culture solution M; and a cover 1 for covering the stirring means and the liquid surface of the culture solution M is disposed above the stirring means. Carbon dioxide is fed to the space formed by the cover 1, and the carbon dioxide is dissolved in the culture solution M by the stirring means. By using the raceway-pond type culture tank, the culture cost can be controlled and a sufficient amount of carbon dioxide can be dissolved in the culture solution even in the shallow depth of water.

Description

  The present invention relates to a raceway pond culture tank.

  In recent years, from the viewpoint of suppressing the emission of greenhouse gases such as carbon dioxide, the idea that the amount of carbon dioxide absorbed by the plant and the amount of carbon dioxide generated when the plant is incinerated is equivalent, that is, “ The concept of “carbon neutral” is spreading. For this reason, the use of so-called biomass fuels (for example, lipids such as triglycerides, alcohols such as ethanol) produced from raw materials derived from biomass resources has attracted more attention than before.

  Examples of biomass resources that can be used as raw materials for biomass fuel include soybeans, corn, and palms. When these edible plants are used as the above biomass resources, there are concerns about food shortages and cultivated land. The problem of deforestation may occur. Therefore, as an alternative to the above biomass resources, photosynthetic microorganisms such as protozoa that live widely in ponds, lakes, etc. have the same photosynthetic ability as plants, from water and carbon dioxide to lipids, carbohydrates It is known that tens of mass% is accumulated in the cell. This production amount is higher than that of plants, specifically, more than 10 times per unit area of palm, which is said to be high in the production amount of lipids, carbohydrates, etc. It is an effective means.

  Thus, as a culture method for artificially culturing photosynthetic microorganisms, for example, Patent Document 1 describes a method using a raceway pond.

Japanese Patent No. 3524835

  Usually, in a race way pond type culture tank, a paddle or the like is used as a stirring means for a culture solution flowing through a culture path constituting the race way pond type culture tank. However, in the case of a raceway pond culture tank for culturing photosynthetic microorganisms, the water depth is about 10 cm to 30 cm, which is shallower than usual. The reason for this is to uniformly irradiate sunlight to the photosynthetic microorganisms present at the bottom of the culture path. And it becomes possible to perform sufficient photosynthesis by irradiating all the photosynthesis microorganisms with sufficient sunlight in this way.

  However, in a culture solution having such a shallow water depth, it is not possible to ensure the aeration depth of carbon dioxide. Therefore, in order to dissolve sufficient carbon dioxide in the culture solution having such a shallow water depth, an excessive amount of carbon dioxide must be brought into contact with the culture solution, resulting in an increase in culture cost.

  The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a raceway pond type culture tank capable of suppressing culture costs and dissolving a sufficient amount of carbon dioxide in a culture solution even at a shallow water depth. It is to be.

  As a result of intensive studies to solve the above problems, the present inventors have a cover on the stirring means in the raceway pond culture tank, and by supplying carbon dioxide inside the cover, the culture cost can be suppressed, The present inventors have found that a raceway pond type culture tank capable of dissolving a sufficient amount of carbon dioxide in a culture solution even at a shallow water depth can be provided.

  That is, the gist of the present invention is a raceway pond type culture tank in which a stirring means is provided in a culture path through which a culture solution flows, and the culture solution is stirred by the stirring means, above the stirring means, and A cover that covers the liquid surface of the stirring means and the culture solution is provided, carbon dioxide is supplied to a space formed by the cover, and the carbon dioxide is dissolved in the culture solution by the stirring means. The present invention relates to a raceway pond type culture tank.

  ADVANTAGE OF THE INVENTION According to this invention, the culture cost can be suppressed and the raceway pond type culture tank which can melt | dissolve a sufficient amount of carbon dioxide in a culture solution can be provided even in shallow water depth.

It is a perspective view showing typically the race way pond type culture tank concerning a first embodiment. It is a figure which represents typically a specific example of the stirring means applicable to the raceway pond type culture tank which concerns on 1st embodiment. In the raceway pond type culture tank concerning a first embodiment, it is a figure showing typically signs that a cover is removed using the stirring means shown in FIG. FIG. 3 is a cross-sectional view schematically showing the vicinity of the stirring means in the raceway pond culture tank using the stirring means shown in FIG. 2. FIG. 3 is a perspective view schematically showing the vicinity of the stirring means in the raceway pond culture tank using the stirring means shown in FIG. 2.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail. However, the present embodiment is not limited to the following contents, and can be arbitrarily changed and implemented without departing from the gist thereof. .

<First embodiment>
FIG. 1 is a perspective view schematically showing a raceway pond culture tank according to the first embodiment. As shown in FIG. 1, the raceway pond type culture tank R according to the first embodiment includes a stirring means P (not shown in FIG. 1) in the culture path 8 through which the culture solution M flows. A raceway pond type culture tank in which the culture medium M is agitated by the agitation means P, and a cover that covers the liquid level of the agitation means P and the culture medium M above the agitation means P. 1 is provided, carbon dioxide is supplied to a space formed by the cover 1 (that is, inside the cover 1), and the carbon dioxide is dissolved in the culture medium M by the stirring means P. 1 and 3, the arrow shown in the culture medium M represents the direction of the flow of the culture medium M, and the arrow shown around the axis of the support material 2 represents the rotation direction of the support material 2. Yes.

  As a specific method for supplying carbon dioxide, in FIG. 1, a carbon dioxide supply path 4 such as a pipe or a pipe is connected to the upper surface of the cover 1. The carbon dioxide supply path 4 is connected to the carbon dioxide supply source 3 via the gas supply amount adjustment valve 5, and the raceway pond culture tank R according to the first embodiment has such a configuration, so that the cover 1 Carbon dioxide can be supplied inside.

  In addition, what can be cultured in the raceway pond type culture tank R according to the first embodiment is not particularly limited as long as the effects of the present invention are not significantly impaired. However, from the viewpoint that carbon dioxide is efficiently dissolved in the culture medium M, preferably an organism cultured using carbon dioxide, more preferably a photosynthetic organism, more preferably a photosynthetic microorganism, even more preferably an algae, especially Euglena is preferable.

  Euglena is a group of flagellates, including Euglena, which is famous as a motile algae. Most Euglena has a chloroplast and photosynthesis and autotrophic life, but there are also predatory and absorption nutrients. Euglena is a genus classified into both zoology and botany.

The composition of the culture solution M may be determined according to the type of organism to be cultured. For example, when euglena is cultured using the raceway pond type culture tank R according to the first embodiment, the culture solution M includes, for example, a culture solution to which nutrient salts such as a nitrogen source, a phosphorus source, and minerals are added, for example, Modified Cramer-Myers medium ((NH ₄ ) ₂ HPO ₄ 1.0 g / L, KH ₂ PO ₄ 1.0 g / L, MgSO ₄ .7H ₂ O 0.2 g / L, CaCl ₂ · 2H ₂ O 0. 02 g / L, Fe ₂ (SO ₂ ) ₃ · 7H ₂ O 3 mg / L, MnCl ₂ · 4H ₂ O 1.8 mg / L, CoSO ₄ · 7H ₂ O 1.5 mg / L, ZnSO ₄ · 7H ₂ O 0 _{.4mg / L, Na 2 MoO 4} · 2H 2 O 0.2mg / L, CuSO 4 · 5H 2 O 0.02g / L, thiamine hydrochloride (vitamin _B 1) 0.1mg / L, cyanocobalamin (bi Min _B 12), can be used (pH 3.5)). Note that (NH ₄ ) ₂ HPO ₄ can also be converted to (NH ₄ ) ₂ SO ₄ or NH ₃ aq.

  Further, the pH of the culture medium M is preferably 2 or more, and the upper limit thereof is preferably 6 or less, more preferably 4.5 or less. By setting the pH to the acidic side, the photosynthetic microorganisms can grow more dominantly than other microorganisms, so that contamination can be suppressed.

  The cover 1 is provided above the stirring means P (the specific configuration, functions, etc. will be described later) and so as to cover the liquid surface of the stirring means P and the culture medium M. The size of the cover 1 is not particularly limited, but it is assumed that the stirring means P can be completely covered. When the lower part of the cover 1 comes into contact with the liquid level of the culture solution M, the cover 1 receives the flow of the culture solution M, in other words, the cover 1 inhibits the flow of the culture solution M. Such contact may be made as long as the effect is not significantly impaired. Further, when the cover 1 is too large compared to the stirring means P (that is, when the space formed by providing the cover 1 is too large), the amount of carbon dioxide that is not dissolved in the culture medium M may be excessive. There is sex.

  The shape of the cover 1 is not particularly limited. In the first embodiment shown in FIG. 1, a quadrangular shape (that is, a half regular octagon shape) is used, but a semi-cylindrical shape or the like may be used.

  Further, the material constituting the cover 1 is not particularly limited. Examples of the material constituting the cover 1 include resins and metals, and these may be used alone or in any combination of two or more. However, since the culture medium M is stirred inside the cover 1 and mist (spray) of the culture medium M is very likely to be generated, a material that does not corrode by the culture medium M should be used as the material constituting the cover 1. Is particularly preferred.

  The support member 2 is fixed with a parallel stirring means 6 and a vertical stirring means 7 in the stirring means P described later. The material constituting the support material 2 is not particularly limited. However, as in the case of the cover 1, a material that is not corroded by the culture medium M and that can securely fix the parallel stirring means 6 and the vertical stirring means 7 should be used. preferable.

  Further, the length of the support member 2 is not particularly limited. However, the support member 2 is usually configured to be connected to drive means (not shown) via a gear, a belt, etc., and the support member 2 is rotated by the drive means (that is, the stirring means P is driven). ). Therefore, it is preferable that the support material 2 has a length that protrudes outside the culture path 8 to such an extent that it can be brought into contact with a gear or a belt. Further, the thickness of the support member 2 is not particularly limited, and may be a thickness having such a strength that the parallel stirring unit 6 and the vertical stirring unit 7 can be reliably fixed.

The carbon dioxide supply source 3 is for supplying carbon dioxide into the cover 1. In the first embodiment shown in FIG. 1, a gas cylinder filled with carbon dioxide is used. However, the carbon dioxide supply source 3 is not limited to a gas cylinder, and for example, exhaust gas from a factory containing carbon dioxide may be used. However, when exhaust gas from a factory or the like is used as the carbon dioxide supply source 3, it is preferable to use a gas that has been previously cultured, for example, from which a component that inhibits the growth and cultivation of photosynthetic microorganisms has been removed. As a device for removing such components (for example, a sulfur oxide (SO _x ) or nitrogen oxide (NO _x ) removal device), any known device can be used, and the installation location thereof is also arbitrary. For example, the gas previously removed by the apparatus may be circulated through the carbon dioxide supply path 4 (described later), or the apparatus is provided in the upper part of the cover 1, and the exhaust gas before removal is supplied to the carbon dioxide supply path 4. It is good also as a structure which supplies carbon dioxide inside the cover 1 after distribute | circulating and removing the said component with the said apparatus. If the photosynthetic microorganisms to be cultured are resistant to, for example, sulfur oxides or nitrogen oxides or have a purifying action, sulfur oxides or nitrogen oxides need not be removed. Good.

The carbon dioxide supply path 4 connects the inside of the cover 1 and the carbon dioxide supply source 3. The length and constituent materials of the carbon dioxide supply path 4 are not particularly limited, but are preferably as short as possible from the viewpoint of suppressing loss of supplied carbon dioxide as much as possible. Further, it is preferable that the constituent material is not deteriorated by carbon dioxide. In particular, when exhaust gas from a factory or the like is used as the carbon dioxide supply source 3, for example, when an SO _x or NO _x removal device is provided on the top of the cover 1, It is preferable to use a material that does not deteriorate due to components other than carbon dioxide contained in the exhaust gas.

  A gas supply amount adjustment valve 5 that adjusts the flow rate of the gas flowing through the carbon dioxide supply passage 4 is provided in the middle of the carbon dioxide supply passage 4, thereby adjusting the amount of carbon dioxide supplied into the cover 1. be able to. The gas supply amount adjusting valve 5 may be manually operated or automatically operated.

Note that the amount of carbon dioxide to be supplied is not necessarily constant. For example, the supply amount can be varied according to time, weather, or the like. Specifically, the supply amount may be varied according to the type (activity status) of photosynthetic microorganisms to be cultured. For example, if photosynthesis is active in the morning, the amount of carbon dioxide is increased in the morning, if photosynthesis is active in the afternoon, the amount of carbon dioxide is increased in the afternoon, and if photosynthesis is not performed at night, the amount of carbon dioxide is increased at night. Carbon dioxide is supplied according to the activity status of photosynthetic microorganisms, for example, by stopping the supply of carbon (stopping the operation of the entire culture tank). By doing so, it is possible to suppress wasteful consumption of carbon dioxide, in other words, it is possible to prevent wasteful release of carbon dioxide that has not been taken into the photosynthetic microorganism. Incidentally, the raceway pond culture tank R according to the first embodiment is assumed to have a function of supplying carbon dioxide according to the activity state of such photosynthetic microorganisms.
Such a change in the supply amount may be performed manually by operating the gas supply amount adjustment valve 5, or for example, a device in which a program capable of performing the above-described change is recorded (for example, a supply amount according to time). When changing the above, the above operation may be automatically performed by interlocking the gas supply amount adjusting valve 5 with a timer or the like.

  Further, the supply amount may be varied according to the type (activity pattern) of photosynthetic microorganisms to be cultured. For example, when the activity of the photosynthetic microorganisms to be cultured becomes particularly active in the afternoon, normally, photosynthesis is also actively performed in the afternoon. Therefore, the supply amount of carbon dioxide may be increased in the afternoon.

  The amount of carbon dioxide supplied into the cover 1 is not particularly limited. However, from the viewpoint of efficiently dissolving carbon dioxide in the culture medium M while suppressing the culture cost, the cover 1 is set so that the amount of carbon dioxide dissolved in the culture medium M becomes the saturated carbon dioxide concentration of the culture medium M. It is preferable to supply carbon dioxide inside.

  In order to supply such an appropriate amount of carbon dioxide to the inside of the cover 1, for example, a carbon dioxide concentration measuring device, a dissolved carbon dioxide concentration measuring device for the culture solution M, etc. are provided inside the cover 1, and the inside of the cover 1 and the culture solution are provided. It is preferable to measure the carbon dioxide concentration in M. A more appropriate amount of carbon dioxide can be supplied to the inside of the cover 1 by changing the supply amount of carbon dioxide based on the measured value.

  In addition, the cover 1 may be brought into contact with the culture medium M so as not to inhibit the flow of the culture medium M, and the culture may be performed while measuring the pressure and carbon dioxide concentration inside the cover 1. In this way, for example, when carbon dioxide is insufficient and the pressure in the cover 1 drops, carbon dioxide is supplied, and when the pressure inside the cover 1 reaches a predetermined value, the supply can be stopped. In addition, the amount of excess carbon dioxide (that is, the amount of carbon dioxide released to the outside) can be reduced more reliably.

  Furthermore, as described above, when the cover 1 is brought into contact with the culture medium M to such an extent that the effects of the present invention are not significantly impaired, carbon dioxide is supplied into the cover 1 to dissolve the carbon dioxide in the culture medium M. In consideration of the amount of carbon dioxide released from the liquid M, the amount of carbon dioxide supplied into the cover 1 may be controlled.

  Next, a specific example of the stirring means P applicable to the raceway pond culture tank R according to the first embodiment will be described with reference to FIG.

  FIG. 2 schematically shows a specific example of the stirring means P applicable to the raceway culture apparatus R according to the first embodiment (hereinafter referred to as “stirring means according to the first embodiment” as appropriate). FIG. The stirring means P according to the first embodiment shown in FIG. 2 includes a parallel direction stirring means 6 that performs stirring in a direction parallel (that is, the same direction) or substantially parallel to the flow direction of the culture solution M, and a flow direction. And a vertical stirring means 7 for stirring in a vertical or substantially vertical direction. And the parallel direction stirring means 6 and the vertical direction stirring means 7 are being fixed to the support material 2 so that all may become equal intervals. In addition to the function of stirring the culture medium M, the stirring unit P according to the first embodiment also has a function of creating a flow of the culture medium M (that is, a function as a circulation unit of the culture medium M). .

  As shown in FIG. 2, in the stirring means P according to the first embodiment, plate-shaped blades are used as the parallel direction stirring means 6, and comb-shaped blades are used as the vertical direction stirring means 7. Further, the number of the parallel direction stirring means 6 and the vertical direction stirring means 7 fixed to the support member 2 is four in FIG. 2, but the number of each fixed means is limited to four. It is not something. Further, the numbers of the parallel stirring means 6 and the vertical stirring means 7 may be different. Further, in FIG. 2, the parallel direction stirring means 6 and the vertical direction stirring means 7 are alternately provided on the support member 2, but are not necessarily provided alternately. Further, the number of comb portions 7a (described later) constituting the vertical direction stirring means 7 is not particularly limited.

  Moreover, the parallel direction stirring means 6 shown in FIG. 2 is formed by bending its end (the side not fixed to the support member 2). As shown in FIG. 2, the plate-like blade having a shape in which the end of the parallel stirring means 6 is bent, and the bending angle is an obtuse angle, so that carbon dioxide inside the cover 1 is more efficiently contained in the culture medium M. Can be dissolved well.

  The size and thickness of the parallel stirring means 6 and the length and thickness of the vertical stirring means 7 are not particularly limited, and the parallel stirring means 6 and the vertical stirring means 7 are located at the bottom of the culture path 8. The size and length should not be in contact with each other, and the thickness and thickness should be sufficient to maintain the strength of each means.

  FIG. 3 is a diagram schematically showing a state in which the cover 1 is removed using the stirring means shown in FIG. 2 as the stirring means P in the raceway pond culture tank R according to the first embodiment. As shown in FIG. 3, by driving the stirring means P, a sufficient amount of carbon dioxide can be dissolved in the culture medium M having a shallow water depth in the culture channel 8 while suppressing the culture cost. Moreover, the flow of the culture solution M can also be created.

  Here, the parallel direction stirring means 6 and the vertical direction stirring means 7 constituting the stirring means P shown in FIG. 2 will be described with reference to FIGS. 4 is a cross-sectional view schematically showing the vicinity of the stirring means P in the raceway pond culture tank R using the stirring means P shown in FIG. 2, and FIG. 5 uses the stirring means P shown in FIG. FIG. 3 is a perspective view schematically showing the vicinity of a stirring means P in a raceway pond culture tank R. In FIG. 5, only a part of the comb portions 7 a constituting the vertical stirring means 7 is shown for the sake of simplicity of explanation.

  In FIG. 4, the white arrow indicates the direction in which carbon dioxide flows in the cover 1, and the circular shape shown in the culture solution M indicates the carbon dioxide dissolved in the culture solution M. Represents. Moreover, the black solid line arrow represents the direction in which each means (and support material 2) rotates.

As shown in FIG. 4, the carbon dioxide supplied into the cover 1 is uniformly diffused into the cover 1, but the direction of carbon dioxide flow is almost unidirectional by the rotation of the parallel stirring means 6 (in FIG. 4). The counter-clockwise direction with respect to the support material 2), most of the diffused carbon dioxide is forcibly brought into contact with the culture medium M together with the parallel stirring means 6 (that is, carbon dioxide is pushed into the culture medium M). Will be). The carbon dioxide forced to come into contact with the culture medium M by the parallel stirring means 6 is dissolved in the culture medium M, and the carbon dioxide that has not been completely dissolved exists between the culture medium M and the cover 1. It is discharged to the outside through.
In the embodiment shown in FIG. 4, the end of the cover 1 and the culture medium M are not in contact with each other. However, as described above, the end of the cover 1 and the culture medium M are brought into contact with each other, thereby carbon dioxide. It is good also as a structure which does not discharge | release outside.

  Further, the stirring of the culture medium M is repeated by the parallel stirring means 6 and the vertical stirring means 7, and the mist (splash) of the culture liquid M is scattered inside the cover 1 and is a space filled with carbon dioxide. The droplets are exposed to. Therefore, the droplets easily dissolve carbon dioxide, which is the surrounding atmosphere, and the droplets in which carbon dioxide has been dissolved in this way again become the culture solution M and flow through the culture path 8.

  As described above, the cover 1 is provided above the stirring means P and covers the liquid surfaces of the stirring means P and the culture medium M, and carbon dioxide is supplied into the cover 1, so that the culture medium M can be efficiently used. It is possible to dissolve carbon dioxide. Even if the stirring means P does not have the parallel direction stirring means 6 or the vertical direction stirring means 7 and the stirring means P is, for example, a screw or the like, for example, due to the turbulence of the air flow caused by the water flow or the generated droplets, the above-mentioned Has the same effect as the effect.

  Moreover, in the raceway pond type culture tank R according to the first embodiment, since the stirring means P shown in FIG. 2 is used as the stirring means, the following advantages are also obtained.

  When cultivating photosynthetic microorganisms using a raceway pond culture tank, the culture medium tends to move only in a two-dimensional direction (ie, a direction perpendicular to the water depth direction) because the culture medium is usually shallow. There is a problem that it is difficult for the culture medium to move in the depth direction. Therefore, even if the depth of the culture solution is adjusted to such a shallow depth that sunlight can reach the photosynthetic microorganisms present at the bottom of the culture path, the culture conditions are still likely to be insufficient. Therefore, it becomes easy to separate into two layers, a photosynthetic microorganism layer that exists near the liquid surface of the culture solution that is sufficiently irradiated with sunlight, and a photosynthetic microorganism layer that exists at the bottom of the culture path where sunlight is difficult to be irradiated. There is a problem that mixing of the layer close to the liquid surface) and the lower layer (layer close to the bottom of the culture path) is difficult to perform, and uniform culture is difficult to be performed.

  However, by using the stirring means P according to the first embodiment, the parallel direction stirring means 6 has an action of forming the flow of the culture medium M in addition to the action of dissolving carbon dioxide. Furthermore, since the parallel stirring means 6 is driven so as to scoop up the culture medium M from the bottom of the culture path 8 (that is, scoop up the culture medium M from the bottom), the vertical direction of the culture medium M in the culture path 8 (FIG. 4 in the vertical direction of the paper).

  Further, as shown in FIG. 5, when the vertical stirring means 7 is driven, after the comb portion 7 a constituting the vertical stirring means 7 is moved, as shown by the black thin solid arrows in FIG. , Perpendicular to or substantially perpendicular to the flow direction of the culture medium M. Although not strictly perpendicular, it is referred to as “vertical” in order to simplify the description. Therefore, by using the stirring means P according to the first embodiment, not only the vertical stirring of the culture medium M by the parallel stirring means 6 but also the stirring in the direction perpendicular to the flow direction of the culture liquid M is performed. You can also

  Therefore, by using the agitation means P shown in FIG. 2 as the agitation means in the raceway pond culture tank R according to the first embodiment, it is parallel to the flow direction of the culture medium M (that is, the same direction as the flow direction). In addition, the stirring of the culture medium M in the vertical direction and the vertical direction of the culture medium M can be performed by one integrally formed stirring means, and in addition to the promotion of carbon dioxide dissolution in the culture medium M, the uniform culture medium M It is also possible to perform stirring.

<Summary>
The raceway pond culture tank R according to the present embodiment has been specifically described using the stirring means P shown in FIG. 2 as the stirring means, but is applied to the raceway pond culture tank R according to the present embodiment. The possible stirring means is not limited to the stirring means P shown in FIG. That is, as the stirring means provided in the raceway pond culture tank R according to the present embodiment, any known stirring means can be used. The number of stirring means provided in the raceway pond culture tank R is also arbitrary, and the cover 1 may be provided according to the number of stirring means provided.

  Furthermore, as described above, the stirring means P according to the first embodiment also has a function of creating a flow of the culture solution M (that is, a function as a circulation means of the culture solution M). The raceway pond culture tank R according to the present embodiment may be combined with a stirring means that does not have a function as a circulation means and a circulation means.

  In the raceway pond culture tank R according to the first embodiment shown in FIG. 1, carbon dioxide is directly supplied from the carbon dioxide supply source 3 to the inside of the cover 1. Carbon dioxide is dissolved in the culture solution M by another dissolving means (not shown), and the carbon dioxide is diffused into the cover 1 when the culture solution M in which the carbon dioxide is dissolved passes through the lower part of the cover 1. Thus, the carbon dioxide may be supplied into the cover 1. By setting it as such a structure, the carbon dioxide diffused inside the cover 1 can be dissolved again in the culture solution M, the amount of carbon dioxide diffused outside can be reduced, and culture | cultivation cost can be reduced by extension.

  In addition, it will be apparent to those skilled in the art that the above-described content can be modified as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Cover 2 Support material 3 Carbon dioxide supply source 4 Carbon dioxide supply path 5 Gas supply amount adjustment valve 6 Parallel direction stirring means 7 Vertical direction stirring means 7a Comb portion 8 Culture path M Culture solution P Stirring means R Raceway pond type culture tank

Claims (3)

A raceway pond type culture tank provided with stirring means in the culture path through which the culture solution flows, and stirring the culture solution with the stirring means,
A cover is provided above the stirring means and covers the liquid level of the stirring means and the culture solution,
A raceway pond culture tank, wherein carbon dioxide is supplied to a space formed by the cover, and the carbon dioxide is dissolved in the culture solution by the stirring means. The stirring means is
Parallel direction stirring means for stirring in a direction parallel or substantially parallel to the flow direction of the culture solution;
Vertical stirring means for stirring in a direction perpendicular or substantially perpendicular to the flow direction;
A support for fixing the parallel stirring means and the vertical stirring means;
The raceway pond culture tank according to claim 1, comprising at least The parallel stirring means is a plate-shaped blade;
The raceway pond culture tank according to claim 1 or 2, wherein the vertical stirring means is a comb blade.

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